In "people moving" transportation systems for urban areas, increased passenger throughput, low operating cost, and operating flexibility are essential factors for satisfying growing transportation needs. Such factors can be provided only by highly automated systems. Heretofore, automated transit systems utilizing computer devices for controlling speed headway have been applied to electric rail systems for both steel wheel and rubber tired vehicles. Prior developments have also included combustion engine powered vehicles guided and controlled from signals emanating from a buried wire. None of these technologies have projected or demonstrated the capability of safely operating vehicles at the high speed and very close headways commensurate with very high passenger throughput while maintaining the operating flexibility that is necessary.
Inductively coupled rubber tired transit systems as described in U.S Pat. Nos. 3,914,562 & 4,331,225 have demonstrated the potential for satisfying the above requirements. These systems can not only transfer power, but can also provide guidance and control inputs to vehicles (magnetically) from an inductor in the roadway to a receiver inductor in the vehicles. Such an arrangement would allow vehicle routes to be switched and reset almost instantaneously by electromagnetic means. Moreover, since power collectors require no physical contact with the roadway, major mechanical constraints to vehicle operation are removed.
Inductively coupled power systems for electric vehicles heretofore disclosed utilized a continuous power inductor which required a large amount of ampere turns in the roadway inductor in order to transfer the required power. This not only increased overall input power requirements but also made it necessary to constrain undesirable electromagnetic effects on adjacent structures or devices to tractable levels. In such inductive power systems, the ampere turns are required only at positions where vehicles are coupled. However, it is not feasible to separately supply and to switch on and off only the short sections of a continuous roadway inductor that are occupied. It is therefore desirable to operate a roadway power system (`powerway`) as extended constant current series circuits, supplied by periodic large power supplies, rather then the costly alternative of using many shorter individual circuits with smaller power supplies. Moreover, it is not feasible to use long continuous bus conductors to supply shorter sections, since the current delivered to the sections would vary widely, depending on the impedance of the particular coupled load.
Accordingly, one general object of the present invention is to provide an improved roadway for an inductively powered transportation system.
Another object of the invention is to provide an inductively powered roadway comprised of a plurality of connected power modules that can be operated as a large series circuit while providing the alternative of activating or deactivating short sections of the roadway as vehicles move over it.
Still another object of the invention is to provide an inductively powered roadway comprised of a plurality of connected power modules with relay means between the modules that enable current supplied to a particular module to bypass the power induction coils to deactivate the module when a vehicle is not on it.
Another object o the invention is to provide an improved inductively powered roadway system comprised of a plurality of modules connected in series and utilizing a vehicle sensing means on each module for controlling bypass means capable of activating or deactivating certain modules forming the roadway.
Another object of the invention is to provide a unique hybird relay for controlling power to or bypassing one or more modules in an inductive power roadway.
Yet another object of the invention is to provide a unique inductive power module construction and a method for fabricating such modules with ease and economy of manufacture